809 



Abstract— The reproductive activity 

 and recruitment of white mullet (Mugil 

 curema) was determined by observa- 

 tions of gonad development and coastal 

 juvenile abundance from March 1992 

 to July 1993. Adults were collected 

 from commercial catches at three sites 

 in northeastern Venezuelan waters. 

 Spawning time was determined from 

 the observation of macroscopic gonadal 

 stages. Coastal recruitment was deter- 

 mined from fish samples collected 

 biweekly by seining in La Restinga 

 Lagoon. Margarita Island, Venezuela. 

 The examination of daily growth rings 

 on the otoliths of coastal recruits was 

 used to determine their birth date 

 and estimate the period of successful 

 spawning. Fish with mature gonads 

 were present throughout the year but 

 were less frequent between September 

 and January when spawning individu- 

 als migrated offshore. In both years, 

 juvenile recruitment to the lagoon 

 was highest between March and June 

 when high densities of 25-35 mm juve- 

 niles were observed. Back-calculated 

 hatching-date frequency distributions 

 revealed maximum levels of successful 

 spawning in December-January that 

 were significantly correlated with peri- 

 ods of enhanced upwelling. The rela- 

 tion between the timing of successful 

 spawning and the intensity of coastal 

 recruitment in white mullet was likely 

 due to variations in food availability for 

 first-feeding larvae as well as to varia- 

 tions in the duration of the transport 

 of larvae shoreward as a result of vary- 

 ing current conditions associated with 

 upwelling. 



Reproduction and recruitment of 

 white mullet iMugil curema) to a tropical lagoon 

 (Margarita Island, Venezuela) as revealed by 

 otolith microstructure* 



Baumar J. Marin E. 



Antonio Quintero 



Institute Oceanografico de Venezuela 



Universidad de Oriente 



Cumana 6101 



Edado Sucre, Venezuela 



E-mail address (for B. J Mann E.): bmann@sucre. udo.edu. ve 



Dany Bussiere 

 Julian J. Dodson 



Departement de biologle 



Unlverslte Laval, 



Ste-Foy 



Quebec, Canada GIK 7P4 



Manuscript approved for publication 

 10 June 2003 by Scientific Editor 



Manuscript received 26 June 2003 at 

 NMFS Scientific Publications Office. 



Fish. Bull. 101:809-821 



White mullet (Mugil curema) is a wide- 

 spread coastal pelagic fish occurring 

 from Massachussetts to southern Brazil. 

 Considered to be catadromous, the juve- 

 nile fish recruit to lagoons and estuaries 

 following a period of offshore spawning 

 (Blaber, 1987; Ibahez-Aguirre, 1993; 

 Ditty and Shaw, 1996). White mullet 

 is an important economic resource 

 supporting many small communities 

 through both fishing and aquaculture 

 (AIvarez-Lajonchere, 1982; Gomez and 

 Cervigon, 1987). Small schools of mullet 

 are captured with gill and "atarraya" 

 nets near the coast and in neritic waters 

 and between 300 and 400 metric tons 

 are sold annually on Margarita Island, 

 Venezuela. 



Reproductive periodicity in white 

 mullet varies over its geographic distri- 

 bution. Several authors have reported 

 protracted or continuous reproduction 

 in tropical waters and generally two 

 spawning peaks per year (Jacot, 1920; 

 Anderson, 1957; Angell, 1973; Moore, 

 1974; AIvarez-Lajonchere, 1976, 1980; 

 Yaiiez-Arancibia, 1976; Rodriguez and 

 Nascimento, 1980; Garcia and Bus- 

 tamente, 1981; Franco, 1986; Ibanez- 

 Aguirre, 1993). Figure 1 summarizes 

 previous work describing the spawning 

 periods of M. curema based on gonad 

 development and estimated according 



to the arrival of juveniles in the coastal 

 zones. The spawning period is quite 

 variable. Angell (1973) suggested that 

 schooling occurs in coastal areas just 

 prior to the offshore spawning migra- 

 tion and that the departure of individu- 

 als for the spawning grounds causes a 

 reduction of the gonadosomatic index in 

 the nearshore populations. Moore ( 1974) 

 also reported that during the spawning 

 period fully ripe fish are rare in coastal 

 collections. Despite these studies, little 

 is known of the factors influencing re- 

 productive patterns of the white mullet. 

 Ibanez-Aguirre (1993) suggested that 

 the timing of reproduction in M. curema 

 in Tamiahua Lagoon, Mexico, is an ad- 

 aptation to avoid competition with juve- 

 niles of the conspecific Mugil cephalus. 

 In areas of favorable thermal regimes, 

 M. curema may penetrate a wider range 

 of salinities and competitively exclude 

 M. cephalus (Moore, 1974). 



The periodicity of white mullet re- 

 production may be related to environ- 

 mental variability that signals periods 

 of optimal early growth and survival. 

 Stability of the water column and suit- 



' Contribution of Quebec-Ocean, Pavilion 

 Alexandre-Vachon, Local 2078, Universite 

 Laval, Quebec, Qc. GIK 7P4. 



